Look ahead vehicle suspension system

ABSTRACT

An active suspension system senses roadway defects and adjusts an active and controllable suspension system of the vehicle before tires come in contact with the defect. The active suspension system identifies a type of defect or debris, e.g., pothole, bump, object, etc., along with the size, width, depth, and/or height information of the defect to more accurately control operation of the suspension system to prepare for, or avoid contact with the roadway defects and obstacles. Imaging techniques are employed to identify the defect or debris. Operation of a serviced cruise control system is controlled to enhance passenger safety and comfort.

FIELD OF THE INVENTION

This invention relates to automobiles and, more particularly, tosuspension systems used in automobiles.

BACKGROUND OF THE INVENTION

Automobile (vehicle) suspension systems are generally known. Anautomobile suspension system isolates to some degree the tires andwheels of the automobile from the occupant-carrying body (vehicle cabin)of the automobile. Passive automobile suspension systems react when thesurface upon which the automobile is traveling changes over distance andtime. For example, when the tires of the automobile come in physicalcontact with a bump as the automobile travels over the bump, thesuspension system reacts to partially isolate the relative motion of thetires from the body to minimize the impact upon the occupants of thevehicle. Likewise, when a tire passes over a pothole in the road, thetire drops into the pothole and the suspension system operates toisolate this relative motion of the tire from the body to minimizeimpact on the occupants.

As automotive technology has advanced, so has the technology ofautomobile suspension systems. Initially, automobile suspension systemsincluded leaf springs that absorbed only the vertical motion of thetimes. However, these springs caused the body to oscillate with respectto the tires. In order to dampen this oscillation, “shocks” were addedto the suspension, which helped to dampen the oscillations caused by thesprings. Further, because it was disadvantageous for the motion ofwheels to be coupled to one another via the suspension system,independent suspension systems were developed that allowed eachtire/wheel to move independently from each other tire/wheel. Otherimprovements introduced variable dampening of the suspension systems.With more stiff suspension settings, the suspension system caused thevehicle to perform better, particularly when cornering. With less stiffsuspension settings, the suspension system provided a smoother ride tothe occupants. In some applications, the stiffness of the suspensionsystem was controllable by the driver.

Each of these prior suspension systems has the distinct disadvantage ofbeing reactive to the motion of the tires/wheels with respect to thebody. Such reactive behavior of the prior automobile suspension systemsfully limited the performance that these suspension systems couldachieve. Further limitations and disadvantages of conventional andtraditional approaches will become apparent to one of ordinary skill inthe art through comparison of such systems with the present inventionsas set forth in the remainder of the present application with referenceto the drawings.

BRIEF SUMMARY OF THE INVENTION

Various aspects of the present invention are found in an active vehiclesuspension system of the present invention. The active vehiclesuspension system of the present invention senses an appearing roadwayhazard and actively alters the behavior of its suspension system inpreparation of an expected meeting with the road hazard. The activevehicle suspension system control therefore prepares the suspensionsystem to effectively mitigate meeting of tires of the vehicle with theroad hazard to cause the suspension system to absorb much of the shockcaused by the meeting and the oscillations of the body (vehicle cabin)that the meeting would otherwise cause to provide improved safety andcomfort to the people inside the cabin.

Embodiments of present invention provide active cruise control operationto provide better sensing capability of roadway conditions so as toenhance the safety of the cruise operation. The roadway hazards sensingoperations of the present invention intercouple with the cruise controlsystem to automatically override cruise control settings, alter thedrive override cruise control settings, and also cause the automobile toactively brake in preparation for impact with the road hazard.

Some embodiments of the present invention provide multilevel decisionmaking capability for a vehicular “sense and control mechanism” for theidentification of each type of the roadway defects based on their width,depth, and height, which requires multilevel control (signal) for hazardmitigation, in a smooth manner, through a smoother adjustment ofsuspension fluid pressure for a jerk free cruise of vehicle over theroadway.

Further aspects of the present invention are found in a safe cruising ofthe vehicle over hostile roadway conditions, with the associatedmechanisms for aiding the driver with adequate audio/visual indication,along with the necessary override control in the event of any humanerror or in the situation of driving beyond the safe limit of speed.

Other features and advantages of the present invention will becomeapparent from the following detailed description of the invention madewith reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an active suspension control system ofthe present invention as applied to for a four wheeled vehicle, withsensor assemblies mounted at strategic points on the chassis of thevehicle for a maximum surveillance of roadway hazards and defects alongwith various inputs through their interfaces, and response variables inan electrical form to controlling processing circuitry;

FIG. 2 is a diagrammatic side schematic view of embodiments of thepresent invention that may be incorporated with a two wheeled vehicle ora four wheeled vehicle, for example;

FIG. 3 is a diagram illustrating a hydraulic pressure control suspensionsystem acting in response to the roadway conditions sensed by atransceiver and controlled by control circuitry according to variousaspects of the present invention;

FIGS. 4 a-4 d are diagrams illustrating various types of transceiversused for detecting roadway defects and hazards used with variousembodiments of the present invention;

FIG. 5 is a diagram illustrating the positioning of several detectorsonboard a vehicle chassis along with one method of scanning roadwaycharacteristics on a time-shared basis according to one or moreembodiments of the present invention;

FIG. 6 is a diagram illustrating a processing of collecting andprocessing roadway images for understanding of the complete roadwaycharacteristics for subsequent decision making in adjusting suspensionsystem control, cruise control, and indications provided to the driveraccording to aspects of the present invention;

FIG. 7 is a diagram illustrating various quantities that are measuredand converted to respective electrical input signal and provided to aprocess and control unit for processing to produce control signals foractuating control mechanisms of an active suspension control system ofthe present invention;

FIG. 8 is a flowchart illustrating operations that are performed withimplementation of a look ahead suspension system in accordance with thepresent invention;

FIG. 9 is a diagram illustrating detection of roadway curvature bysensors that sense a roadway border and indicate a measured steeringangle along with various forces that are acting on the moving vehicle tokeep the vehicle in equilibrium in the radial direction according toaspects of the present invention;

FIG. 10 is a block diagram illustrating a vehicle control overridemechanism that operates based upon detected and manual thresholdadjustments of variables under consideration in accordance with anembodiment of the present invention.

DETAILED DESCRIPTION

FIG. 1 is a traffic system 100, comprising a four wheeler vehicle 101 ona roadway 103, which has deployed the look ahead suspension technique,having a capability to visualize roadway defects such as potholes andbumps, 105, and obstacle 107 well ahead in anticipation, which can causeundesirable shocks and oscillations to the vehicle and hencediscomforting people inside it. The suspension adjustment is done beforevehicle physically coming in contact with the defects, to mitigate theireffects.

The front left tire assembly 117, is associated with a transceiverdetector assembly 147, and further associated with an adjustablesuspension 127. The transceiver 147 can transmit electromagnetic waves,according to an embodiment of the present invention, towards the roadwayand receives the reflected wave, which is characterized by the roadwaycharacteristics.

The front right tire assembly 119, is associated with a transceiverdetector assembly 149, and further associated with an adjustablesuspension 129. The transceiver 149 can transmit electromagnetic waves,according to an embodiment of the present invention, towards the roadwayand receives the reflected wave, which is characterized by the roadwaycharacteristics.

The rear left tire assembly 121, is associated with a transceiverdetector assembly 151, and further associated with an adjustablesuspension 131. The transceiver 151 can transmit electromagnetic waves,according to an embodiment of the present invention, towards the roadwayand receives the reflected wave, which is characterized by the roadwaycharacteristics.

The rear right tire assembly 123, is associated with a transceiverdetector assembly 153, and further associated with an adjustablesuspension 133. The transceiver 153 can transmit electromagnetic waves,according to an embodiment of the present invention, towards the roadwayand receives the reflected wave, which is characterized by the roadwaycharacteristics.

FIG. 1 is a diagram illustrating an active suspension control system ofthe present invention as applied to for a four wheeled vehicle, withsensor assemblies mounted at strategic points on the chassis of thevehicle for a maximum surveillance of roadway hazards and defects alongwith various inputs through their interfaces, and response variables inan electrical form to controlling processing circuitry. In an embodimentaccording to the present invention, receivers transceiver 147, 149, 151,and 153 convert reflected light from the roadway to a proportionalelectric signal and apply this signal to the control processing unit125, which in turn controls the adjustable suspensions elements, 147,149, 151, and 153, before the wheels of the vehicle come in physicalcontact with the roadway defects 105 and 107.

The control processing unit 125 is associated with input system 161,which has measured information related to a cruise control, such asmotion sensor output, velocity detector output, etc., which leads todecision making with respect to the thresholds that manually setvariables and finally actuating a response system, 163.

The control processing unit 125 and Input system 161 are also associatedwith a Response system 163, which responds based upon the decision madewith respect the manually set variables and finally actuating safetydevices such as a Airbag system, Driver indicator, Steering override,Braking override, Acceleration override, Cruise control, and Deflectionsystem.

FIG. 2 is a diagrammatic side schematic view of embodiments of thepresent invention that may be incorporated with a two wheeled vehicle ora four wheeled vehicle, for example. Various sensing and detectingmechanisms aboard in 201 and each one of them have separate interfacewith the central process and control circuitry. The suspension controlpart is emphasized with the brief description of the hydraulic system.

In an embodiment according to the present invention, 249 can be anyclass of vehicle; a two wheeler, a car, a truck, etc., with front tireassembly 237 associated, with its controllable suspension 241, and(transceiver) detector 245. The detector sends signal 243 toward theroadway at an angle 249 for detecting the roadway defect 247 towardwhich the front wheels of the vehicle are approaching in a short periodof time; receives the reflected signal, and sends it to transceiverinterface 211 of the control circuitry 205.

In an embodiment according to the present invention, 249 can be anyclass of vehicle; a two wheeler, a car, a truck, etc., with rear tireassembly 229 associated, with its controllable suspension 227, and(transceiver) detector 233. The detector sends signal 235 toward theroadway at an angle 251 for detecting the roadway defect 247 towardwhich the rear wheels of the vehicle are approaching in a short periodof time; receives the reflected signal, and sends it to transceiverinterface 211 of the control circuitry 205.

In an embodiment according to the present invention, the suspensioninterface 209 processes the incoming reflected roadway signal sends itto the processing circuitry 217, generates the necessary control signalthrough the response system interface 215 and suspension interface 209,which goes to hydraulic system 223, further controlling the suspension227 and 241.

In an embodiment according to the present invention, the driving inputsystem 203 also generates various signal inputs 249, can be any class ofvehicle; a two wheeler, a car, a truck, etc., with front tire assembly237 associated, with its controllable suspension 241, and (transceiver)detector 245. The detector sends signal 243 toward the roadway at anangle 249, indicated for detecting the roadway defect 247 toward whichthe front wheels of the vehicle are approaching in a short period oftime; receives the reflected signal, and sends it to suspensioninterface 209 of the control circuitry 205.

In an embodiment according to the present invention, the driving inputsystem 203 also generates various signal inputs 249, can be any class ofvehicle; a two wheeler, a car, a truck, etc., with rear tire assembly229 associated, with its controllable suspension 221, and (transceiver)detector 233. The detector sends signal 235 toward the roadway at anangle 251, indicated for detecting the roadway defect 247 toward whichthe rear wheels of the vehicle are approaching in a short period oftime; receives the reflected signal, and sends it to suspensioninterface 209 of the control circuitry 205.

FIG. 3 is a diagram illustrating a hydraulic pressure control suspensionsystem acting in response to the roadway conditions sensed by atransceiver and controlled by control circuitry according to variousaspects of the present invention. The system 301 includes a hydraulicactuated structure to provide the controllable suspension 227 and 241 ofFIG. 2. The system 301 adjusts fluid pressure inside cylinder 313 of thesuspension 301 using a Hydraulic pump 303. The cylinder 313 is mountedon the vehicle chassis using the fixtures 315 and 317 with its internalpressure adjusted in response to the roadway conditions. Moving cylinder314 moves with respect to cylinder 313 and based with its position andability to move with cylinder based upon the amount of hydraulic fluidwithin cylinder 313. The cylinder 313 and moving cylinder 314 areconstructed so that the range of motion of the moving cylinder 314 islimited with respect to the cylinder 313. For example, the movingcylinder 314 may be limited in its relative motion with respect to thecylinder such that positions 321 and 322 on the moving cylinder 314define a range of motion with respect to the edge 320 of cylinder 313.

In an embodiment according to the present invention, the hydraulic pump303 is used to react in response to the control signal 303, generatedfrom the control circuitry 205 of FIG. 2. The control signal 303 drivesa servomotor 305, coupled to a pump 307 that is operable to pumphydraulic fluid from the Fluid tank 309 into and out of the cylinder 313of the suspension 313.

In an embodiment according to the present invention, the fluid pressureremains normal under normal roadway conditions. When the vehicle wheelsencounter a pothole, fluid pressure is increased and when the vehiclewheels encounter a bump the fluid pressure is decreased.

FIGS. 4 a-4 d are diagrams illustrating various types of transceiversused for detecting roadway defects and hazards used with variousembodiments of the present invention. FIG. 4 a is a 1D (one dimensional)array of LEDs used for sending optical signal focused using a reflectortowards roadway as shown in FIG. 4 b. FIG. 4 c is one of the severaltypes of receivers used for sensing the reflected electromagnetic signal(in the form of light) from the roadway. For better receiver efficiency,the low intensity reflected light from the roadway obstacle, is made toincident on a reflector similar to that of FIG. 4 b which helps incapturing more light on to a 1D array of photo diodes or phototransistors as shown in FIG. 4 d. In FIG. 1 a, a 1D array of LEDs 403acts as a source of light focused at an angle towards the roadwaydefects. The 1D array of LEDs is placed at the focal point of areflector as shown in FIG. 4 b to send an optimum intensity of lighttoward the roadway, with parallel rays. Similarly a reflector can alsobe used to capture more light by placing the array of photodiodes (PDs)at the focal point of the reflector as shown in FIG. 4 c.

In an embodiment according to the present invention, in FIG. 4 a, anarray, 403, comprising a plurality of LEDs 405, acts as a source lightsignal 409, which will emitted in all direction, causing the lightintensity to fall rapidly even in a small distance from the source. Thisrequires a type of the reflector 411, as shown in FIG. 4 b, to focuslight in one direction.

In an embodiment according to the present invention, in FIG. 4 b, a 1Darray of LEDs 413 is located in the focal point of a reflector 411 formaking the light, parallel and more focused ray, 415. By rotating thereflector 411 over the axis of the 1D array of LEDs 413, it is possibleto change the direction of the light beam.

In an embodiment according to the present invention, the reflected lightfrom the roadway defects 247, in FIG. 2 is converted into electricalsignal, by a PD 423 and amplified by an amplifier 427 as shown in FIG. 4c. An array of PDs, 421 in this figure can also be used in the place ofsingle PD, wherein the electrical signal from each of these PDs can besummed to get a better result for effective detection of the roadwaydefects, increasing the capture area for the reflected light from theroadway.

In an embodiment according to the present invention, 1D array of PDs canbe mounted at the focal point of a reflector 429 as shown in FIG. 4 dfor capturing maximum reflected light, according to one embodiment ofthe present invention. The reflected light from the roadway defects 247,in FIG. 2 will converge at the focal point of the reflector 429 toenhance conversion efficiency of the detector and hence the sensitivity.This reflected light signal is a measure of the defect, their type(pothole or a bump) and size.

FIG. 5 is a diagram illustrating the positioning of several detectorsonboard a vehicle chassis along with one method of scanning roadwaycharacteristics on a time-shared basis according to one or moreembodiments of the present invention. For example, FIG. 5 illustrates adetector assembly placed on the vehicle chassis for roadway defectdetection and look ahead suspension control, velocity measurement,acceleration measurement, cruise control, collision control, and roadwayobstacle sensing. Further, FIG. 5 also illustrates the manner in whichthe values of these desired variables are sensed and fed into a processand control circuit for actuating a response system. A simple scanningmechanism gathers data on these variables in a timeshared manner with aperiod of the scanning cycle, in the order of microsecond or less, whichallows a comfortable scanning of the roadway conditions and otherparameters of vehicle driving information, when the vehicle is moving atits maximum speed limit.

In an embodiment of the present invention, the roadway defect detectorassembly and a controllable suspension device are associated with theRear left tire assembly 509, Front left tire assembly 511, Front righttire assembly 513, and Rear right tire assembly 515. Each of the roadwaydefect detector controls the respective suspension device, independentof each other, against the roadway defects 531, and 533.

In an embodiment according to the present invention, detector 519mounted on the front part of the chassis and detector 517 mounted on therear part of the chassis can sense larger roadway obstacles, both living527, and non-living 529. Each of these sensors sense obstacles andgenerate control signal to actuate, the indication to driver and theoverride mechanisms. They also trigger airbag mechanism under highimpact or sudden braking conditions.

In an embodiment according to the present invention, the detectors 501,503, 505, and 507 mounted on the left and right side of the vehiclechassis can detect the passing vehicles in left and right sidesrespectively in a parallel or an anti-parallel direction. If thesevehicles come closer to this vehicle, an audio/visual indication isgiven to the driver for a safety action from safe distance.

In an embodiment according to the present invention, these detectors501, 503, 505, 507, 517, and 519, which are either point sources or anarray of the detecting elements, as described in FIG. 4, are scanned bya high speed switch to energize these detectors by a battery 523, atdiscrete interval of time. The scanning mechanism is a high speed switchindicated as a wiper 525, swept in the direction 521, coming in contactwith each of the detector terminal for an extremely short time. Duringthe same time the signal is processed and the control signal isgenerated by the processing and control circuitry, and applied to therespective devices, such as cruise control, suspension control,overriding control, airbag control etc. Of course, the scanning may alsobe done via electrical control that is electronically switched.

FIG. 6 is a diagram illustrating a processing of collecting andprocessing roadway images for understanding of the complete roadwaycharacteristics for subsequent decision making in adjusting suspensionsystem control, cruise control, and indications provided to the driveraccording to aspects of the present invention. In one embodiment 601,according to the present invention, a plurality digital cameras mountedon different part of the vehicle chassis as discussed in FIG. 5 sendssnap shots of successive image frames of the roadway characteristicsinto an image processor. The current and the previous frames arecorrelated; on significant difference between these two frames, leads tothe decision of change in the roadway characteristics, to concludeeither as a pothole or a bump of a particular shape and size. Detectionof larger obstacles, moving or stationary can also be done in a similarmanner.

In an embodiment according to the present invention, 625 is the image ofthe roadway comprising image 623 of a defect 627. The informationrelated to the image is stored as a variation in intensity and the colorof the pixels on the camera which is stored in a memory bank 611 througha data bus 621. A previous detected roadway image frame 605, with defectimage 603 is residing in a memory bank 609, transferred on a data bus607 from the same camera.

In an embodiment according to the present invention, the present andprevious frames are compared for the difference proportional to anincremental change in the roadway characteristics. The previous frame isresiding in the memory bank 609 and the current frame in the memory bank611. Both images are compared in the image processor and a decision ismade, whether the vehicle is likely to approach the defect 627 with in ashort period of time estimated based on the velocity of the vehicle.

In an embodiment according to the present invention, the image processorexecutes an internal algorithm to decide whether the change in thesensed roadway characteristics corresponds to a pothole or a bump. Basedon the decision made a Suspension Control signal generator 615 generatesthe necessary signal to actuate the Hydraulic pump 303 of FIG. 3 toadjust the pressure of the fluid in the vehicle suspension, in a correctdirection to mitigate the effect of the roadway defect 627.

FIG. 7 is a diagram illustrating various quantities that are measuredand converted to respective electrical input signal and provided to aprocess and control unit for processing to produce control signals foractuating control mechanisms of an active suspension control system ofthe present invention. FIG. 7 provides an expanded view 701 of theControl processing unit 125 of the FIG. 1. This figure gives a completepicture of status monitoring and control status of a vehicle on aroadway. Several inputs that are measured or detected and thecorresponding control signals generated are shown in more detail.

According to an embodiment of the present invention, Receive inputsignal 703, comprises Cruise control 705 sensing the vehicle cruiseoperation and provides the input to the Monitor/Process Input signals723 for processing. The processing circuit does the processing of theinformation and generate control signal for a safe cruise of thevehicle.

According to an embodiment of the present invention, Receive inputsignal 703, comprises velocity detecting unit, Velocity 709 and providesthe input to the Monitor/Process Input signals 723 for processing andcontrol signal generation. The processing circuit does the processing ofvelocity information and generate control signal for bringing vehicle toa safe velocity limit.

According to an embodiment of the present invention, Receive inputsignal 703, further comprise a suspension status sensing apparatusSuspension Status 711. The measure of the fluid pressure in thecontrollable suspension device is the input to the Monitor/Process Inputsignals 723 for processing and controlling of the suspension for thecurrent roadway condition.

According to an embodiment of the present invention, Receive inputsignal 703, does comprise a cabin motion sensing apparatus, Cabin Motion713 for sensing the cabin jerking or oscillatory motions happening atthe defective roadway and roadway curvatures spots. An output from theCabin Motion 713 goes to Monitor/Process Input signals 723 unit. In 723,processing of the signal takes place and suspension control signal isgenerated to mitigate the undesirable cabin motion.

According to an embodiment of the present invention, Receive inputsignal 703, does comprise a brake status sensing apparatus, Brake Status715 for sensing the braking condition of the vehicle during the motionsof the vehicle on the roadway. An output from 715 goes toMonitor/Process Input signals 723 unit. In 723, processing of the signaltakes place and a braking override signal will be generated, ifrequired, based on the current brake situation and the roadwayconditions.

According to an embodiment of the present invention, Receive inputsignal 703, does comprise an airbag status sensing apparatus, AirbagStatus 717 for sensing the current status of the airbag duringreasonably heavy impact situations. An output from the 717 goes toMonitor/Process Input signals 723 unit. In 723, processing of the signaltakes place and an airbag trigger signal is issued, if the airbag is nottriggered already, otherwise will not (and maintain the current airbagstatus).

According to an embodiment of the present invention, Receive inputsignal 703, does comprise a steering angle sensing apparatus, SteeringAngle 719 for sensing the current steering angle. An output from the 719goes to Monitor/Process Input signals 723 unit. In 723, processing ofthe signal takes place and a steering guidance will be initiated ifneeded, in roadway curvature spots.

According to an embodiment of the present invention, Receive inputsignal 703, does comprise an acceleration sensing apparatus, AcceleratorStatus 721 for measuring the acceleration of the vehicle under thecurrent roadway conditions. An output from the 721 goes toMonitor/Process Input signals 723 unit. In 723, processing of the signaltakes place and an acceleration control or override signal is generated,proportional to roadway conditions.

According to an embodiment of the present invention, based on the inputfrom 703, the process control circuitry 723 initiates control action bygenerating the control signal and sending them to the respective devicesthrough their interfaces.

According to an embodiment of the present invention, based on theroadway characteristics, one of the output from the Process Input Signal723, goes to a circuit, Non-optimal suspension 725, whose power level isinadequate to drive the Hydraulic pump. A power gate circuit controlledby 725 generates the required electric power. The power level at thisstage is adequate to control a hydraulic pump, 303 of FIG. 3 for thecontrollable 313 (FIG. 3).

According to an embodiment of the present invention, based on theroadway characteristics, one of the output with a plurality of thesignals from the block, Process Input Signal 723, goes to an overridemechanism actuation control 727, labeled Override Situation; therequired power level to actuate the mechanisms, onboard vehicle isboosted in a block 735, to cause to override Braking, Acceleration, andSteering Angle.

According to an embodiment of the present invention, one of thesituation, based on the roadway conditions, one of the output signalfrom the block, Process Input Signal 723, goes to an emergency controlmechanism 729, labeled Emergency Situation, causing to override thecontrol for Braking, Acceleration and steering angle in 737, ifwarranted airbags are triggered in 741 for the safety of the personsinside the vehicle.

According to an embodiment of the present invention, one of the outputsignals from the block, Process Input Signal 723, goes to a circuit 731implemented to provide an interface with the cruise control mechanism,depending on the road conditions, such in a hostile terrain. In anembodiment of the present invention, this is achieved by monitoring theroadway features at an accurate and rapid surveillance at a speedgreater than human perceptibility. When driver fails to react quicklyfor changing conditions of the roadway with the fast movement of thevehicle, Cruise Control 731, override driver and adjusts brakingacceleration etc., in 739. In of the automatic; control, adjustments,and also the roadway conditions are also brought to the notice of thedriver on an audio/visual indication to him on a panel labeled, ProvideDriver Indication 743.

FIG. 8 is a flowchart illustrating operations that are performed withimplementation of a look ahead suspension system in accordance with thepresent invention. The operations 801 of FIG. 8 take place during thelook ahead suspension control operation as described earlier in FIG. 1to FIG. 3, according to an embodiment of the present invention. Asimilar flowchart can explain the automatic control of the other vehicleparameters such as velocity, acceleration, steering angle, brakingposition, etc., during its motion along the roadway.

In an embodiment according to the present invention, when the ignitionis put on at Start 803, all the processing and the control modules arepowered up. When the vehicle is stationary, the detectors that aremounted on the chassis starts sensing the roadway; defects andobstacles, but the suspension control action is initiated only when thevehicle accelerates. The acceleration parameter value is essential forthe processing circuitry to predict or extrapolate the time at which thewheels come in contact the roadway defects, at which point of time thefluid pressure in the suspension should be synchronously adjusted to aproper value depending on the depth or height of the roadway defect.

The control loop enters the state 805 from state 803, where thetransmitter in the form an array of LEDs, as shown in the FIG. 4,transmits signal towards the roadway at an angle determined by thereflector, during a time slot determined by the scanning duration of allthe detectors in a sequence, as described in FIG. 5.

The controller, from state 805, enters the state 807 where it receivesthe reflected electromagnetic signal from the roadway characteristicsand transforms into electrical form and sends this electrical signalinto the processing circuitry to enter the state 809.

Controller, in the state 809, processes the electrical signal, andgenerates the control signal to enter state 811. The controller, instate 813 sends the necessary control signal to drive the hydraulic pumpfor adjusting the fluid pressure in the cylinder of the suspension tomitigate the effect of the jerks due to the roadway defects. Thisoperation repeats by entering back to the state 805.

FIG. 9 is a diagram illustrating detection of roadway curvature bysensors that sense a roadway border and indicate a measured steeringangle along with various forces that are acting on the moving vehicle tokeep the vehicle in equilibrium in the radial direction according toaspects of the present invention. The roadway characteristics sensed atsuch curvature are the roadway border and the tilt; the discontinuitypoint which has different signal reflection characteristic from that ofthe straight road. Another parameter at such spot is the radial drag onthe tangentially moving vehicle.

According to an embodiment of the present invention, the roadwaycurvature 919, radially inward force 903 and outward force 905 and theroadway tilt are natural characteristics of a curvature that aredetected for controlling the motion of the vehicle at such spots, alongwith the suspension control operation.

According to an embodiment of the present invention, the detectors onrear tire and front tire assembly 907, 909, 911, and 913 are placedexactly in front of the wheel, so that then can detect the roadwaydefects more accurately. A detector such as 933 placed close in front ofthe vehicle chassis for the detection of the roadway obstacles can viewthe left roadway border 915 and the right roadway border 917, moreaccurately.

In an embodiment according to the present invention; the steering angle921, a measure of the roadway curvature for displaying on the driver'spanel and also for the cruise control purpose at such roadway curvaturespots, can be measured based on the angle between an emitted ray beam923 and a ray beam 925 of signals from the detector assembly. Thisinformation is used to know on various force parameters that are actingon the vehicle during its passage at such curvature spots. Thecalculation of such forces helps to control the acceleration of thevehicle at such spots for avoiding the dangers of skidding of thevehicle off the roadway or for avoiding hitting with a vehicle in theneighboring lane.

In an embodiment according to the present invention; all the roadwaycurvature parameters are detected and measured and send to the processand control circuitry discussed in 125 of FIGS. 1 and 205 of FIG. 2which makes decision and issue control signal for, adjusting the onboarddevices and display them on the driver's panel and if warranted toactuate the override mechanism for safe cruise of the vehicle.

FIG. 10 is a block diagram illustrating a vehicle control overridemechanism that operates based upon detected and manual thresholdadjustments of variables under consideration in accordance with anembodiment of the present invention. This mechanism ensures the safetyof the vehicle when driver fails to act in time. The detectors mountedon the vehicle chassis, always monitor the roadway conditions and thecurrent response status of the vehicle, under motion. Whenever, anyparameter under monitor exceeds a preset value, the override mechanismacts, along with the necessary indication to the driver on his panel.

In an embodiment according to the present invention, a plurality of theresponse parameters and vehicle system measurements parameters, 1003under consideration are Airbag system, Driver indicator, Steeringoverride, Braking override, Acceleration override, Cruise control, andDeflection control. These parameters are constantly sensed and measuredby the respective sensors and the related electronic system and storedthe inbuilt latches and memories.

In an embodiment according to the present invention, a plurality of theresponse parameters and vehicle system measurements parameters, 1001under consideration and mentioned earlier viz., are Airbag system,Driver indicator, Steering override, Braking override, Accelerationoverride, Cruise control, and Deflection control, needs a threshold toset for each of these parameters, above or below which an action ofoverride take place, implying the failure of the driver to act quicklyand in time.

In an embodiment according to the present invention, the sensedResponses and system measurements 1003 and the corresponding manual setthreshold values are compared in a comparator 1005, each one of themwith a separate comparison with their respective threshold values,producing a difference with associated sign, viz., plus or minus duringcomparison. Depending on the sign of comparison results, a decisionmaking circuit acts to triggers override action and also does update ofthe quantity measured at the present instant of time on a display.

In an embodiment according to the present invention, the status of theairbag is sensed when an airbag needs to deployed. If it is already in adeployed state, the trigger mechanism simply does not to do anything.The quantity that needs to be set as threshold is the impact level. Inthe case of Driver indicator, it is the selection of variables toindicate on the panel and their constant update is the one, which needsto be manually set. Steering override, Braking override, Accelerationoverride, are associated with a set threshold above or below which, theoverride mechanism acts to override the driver actions.

As one of average skill in the art will appreciate the presentdisclosure as one of the new and an elegant method over the prior art ofthe vehicle suspension control. Although there is some way of looking atthe roadway defects and the control of the suspension, one canappreciate the superiority of method and the goal that is achieved asfor the present invention, Simplicity, robustness and compactness of thetransceiver architecture is far more elegant and appreciable. The goalthat can be achieved is far more a feasible technique with more comfort,safety and luxury accomplished, than ever before. As one of averageskill in the art will also appreciate, inferred implementation andmethod to a vast number of other applications, such as velocity sensing,acceleration sensing, cruise control, override mechanism, etc., usingsame method discussed herewith, in the context of the look aheadsuspension implementation.

Although a system and method according to the present invention has beendescribed in connection with the preferred embodiment, it is notintended to be limited to the specific form set forth herein, but on thecontrary, it is intended to cover such alternative, modifications, andequivalents, as can be reasonably included within the spirit and scopeof the invention as defined by this disclosure and appended diagrams

The present invention has also been described above with the aid ofmethod steps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claimed invention.

The present invention has been described above with the aid offunctional building blocks illustrating the performance of certainsignificant functions. The boundaries of these functional buildingblocks have been arbitrarily defined for convenience of description.Alternate boundaries could be defined as long as the certain significantfunctions are appropriately performed. Similarly, flow diagram blocksmay also have been arbitrarily defined herein to illustrate certainsignificant functionality. To the extent used, the flow diagram blockboundaries and sequence could have been defined otherwise and stillperform the certain significant functionality. Such alternatedefinitions of both functional building blocks and flow diagram blocksand sequences are thus within the scope and spirit of the claimedinvention.

One of average skill in the art will also recognize that the functionalbuilding blocks, and other illustrative blocks, modules and componentsherein, can be implemented as illustrated or by discrete components,application specific integrated circuits, processors executingappropriate software and the like or any combination thereof.

Moreover, although described in detail for purposes of clarity andunderstanding by way of the aforementioned embodiments, the presentinvention is not limited to such embodiments. It will be obvious to oneof average skill in the art that various changes and modifications maybe practiced within the spirit and scope of the invention, as limitedonly by the scope of the appended claims.

1. A suspension system used to reduce undesirable motion of a vehicle chassis that travels along a roadway having at least one roadway defect, the suspension system comprising: a front tire assembly; a rear tire assembly; a first adjustable suspension device that couples the front tire assembly to vehicle chassis; a second adjustable suspension device that couples the rear tire assembly to vehicle chassis; a transmitter, mounted on the vehicle chassis, that sends source signals toward the roadway; a receiver mounted on the vehicle chassis, that receives reflections of the source signals from the roadway and, based thereon, generates reflection signals; a processing circuit, communicatively coupled to the receiver, that analyses the reflection signals to identify the at least one roadway defect; and the processing circuit responds to the identification of the at least one roadway defect by interacting with the first adjustable suspension device before the front tire assembly encounters the at least one roadway defect.
 2. The suspension system of claim 1, wherein the receiver comprising a plurality of electromagnetic detectors.
 3. The suspension system of claim 1, wherein the processing circuit responds to the identification of the at least one roadway defect by interacting with the second adjustable suspension device before the rear tire assembly encounters the at least one roadway defect.
 4. The suspension system claim 1, wherein the first adjustable suspension device having a suspension response, and the interaction by the processing circuit with first adjustable suspension device results in tailoring the suspension response to the at least one roadway defect.
 5. The suspension system of claim 1, further comprising a velocity measurement device that delivers a velocity signal to the processing circuit; and the processing circuit adjusts the timing of the interaction based on the velocity signal.
 6. The suspension system of claim 5, further comprising at least one motion sensor that delivers a motion signal to the processing circuit.
 7. The suspension system of claim 1, wherein the transmitter further comprising a plurality of transmitters.
 8. Roadway analysis circuitry used in a vehicle traveling a roadway, the roadway having at least one characteristic, the vehicle having a plurality of adjustable suspension devices, the roadway analysis circuitry comprising: a detector that translates electromagnetic waves reflected from the roadway having the at least one characteristic into roadway signals; processing circuitry, communicatively coupled to the detector, that analyzes the roadway signals from the detector; and the processing circuitry, based on the analysis, selectively sends control signals to at least one of the plurality of adjustable suspension devices.
 9. The roadway analysis circuitry of claim 8, wherein the at least one characteristic comprising a roadway defect.
 10. The roadway analysis circuitry of claim 8, further comprising at least one electromagnetic wave transmitter.
 11. The roadway analysis circuitry of claim 8, wherein the processing circuitry considers vehicular velocity to construct the control signals.
 12. The roadway analysis circuitry of claim 8, further comprising a driver interface circuit coupled to the processing circuitry; and the processing circuitry communicates information relating to the analysis to the driver interface circuit.
 13. The roadway analysis circuitry of claim 12, wherein the information relating to the analysis comprising an alert signal.
 14. The roadway analysis circuitry of claim 8, wherein the detector receives electromagnetic waves reflected from other vehicles; and the processing circuitry analysis signals corresponding to the received electromagnetic waves reflected from other vehicles to identify the other vehicles.
 15. The roadway analysis circuitry of claim 14, wherein the detector comprises a plurality of detectors.
 16. The roadway analysis circuitry of claim 10, wherein the electromagnetic wave transmitter having an adjustable output angle.
 17. The roadway analysis circuitry of claim 16, wherein the processing circuitry controls the adjustable output angle.
 18. The roadway analysis circuitry of claim 17, wherein the control of the adjustable output angle by the processing circuitry comprising scanning.
 19. The roadway analysis circuitry of claim 15, wherein the plurality of detectors comprising a photo-detector array.
 20. A method performed by a processing circuit in an active suspension system of a vehicle that travels along a roadway, the roadway having at least one aspect, the method comprising: receiving roadway signals that correspond to electromagnetic waves reflected off the roadway; analyzing the roadway signals to detect the at least one aspect; generating a first adjustment signal based on the analysis of the roadway signals; and delivering the first adjustment signal to the active suspension system.
 21. The method of claim 20, further comprising receiving velocity signals corresponding to the travel by the vehicle along the roadway; and wherein the generating of the first adjustment signal is also based on the velocity signals.
 22. The method of claim 20, further comprising delivering transmit control signals to cause the generation of the electromagnetic waves that reflect off the roadway.
 23. The method of claim 20, wherein the active suspension system has a first adjustable suspension device and a second adjustable suspension device, the method further comprising: generating a second adjustment signal based on the analysis of the roadway signals; delivering the second adjustment signal to the second adjustable suspension device of the active suspension system; and wherein the first adjustment signal is delivered to the first adjustable suspension device of the active suspension system before the second adjustment signal is delivered to the second adjustable suspension device.
 24. The method of claim 20, wherein the at least one aspect comprising a roadway defect.
 25. The method of claim 20, wherein the at least one aspect comprising roadway curvature.
 26. Roadway analysis circuitry used in a vehicle traveling a roadway having at least one surface defect, the vehicle having a response system, the roadway analysis circuitry comprising: a detector that translates electromagnetic waves reflected from the roadway into roadway signals; processing circuitry that analyzes the roadway signals received from the detector; and the processing circuitry, based on the analysis, selectively sends control signals to the response system.
 27. The roadway analysis circuitry of claim 27, wherein the response system comprising an adjustable suspension system; and the control signals comprising suspension adjustment signals.
 28. The roadway analysis circuitry of claim 27, wherein the response system comprising a driver interface device; and the control signals comprising driver interface signals.
 29. The roadway analysis circuitry of claim 27, wherein the response system comprising a steering system having driver override capability; and the control signals comprising override signals.
 30. The roadway analysis circuitry of claim 27, wherein the response system comprising a braking system having driver override capability; and the control signals comprising override signals.
 31. The roadway analysis circuitry of claim 27, wherein the response system comprising a retractable deflector assembly; and the control signals comprising deflector control signals
 32. The roadway analysis circuitry of claim 27, wherein the response system comprising an airbag system; and the control signals comprising airbag control signals. 